background_image_filename = 'sushiplate.jpg'
sprite_image_filename = 'fugu.png'
 
import pygame
from pygame.locals import *
from sys import exit
 
pygame.init()
 
screen = pygame.display.set_mode((640, 480), 0, 32)
 
background = pygame.image.load(background_image_filename).convert()
sprite = pygame.image.load(sprite_image_filename)
 
# sprite的起始x坐标
x = 0.
 
while True:
 
    for event in pygame.event.get():
        if event.type == QUIT:
            exit()
 
    screen.blit(background, (0,0))
    screen.blit(sprite, (x, 100))
    x+= 10.     #如果你的机器性能太好以至于看不清，可以把这个数字改小一些
 
    # 如果移动出屏幕了，就搬到开始位置继续
    if x > 640.:
        x = 0.    
 
    pygame.display.update()
